Liquid level alarm



May 7, 1940. F, SANDBERG 7 2,199,677

LIQUID LEVEL ALARM I Filed May 1, 1939 INVENTOR. ART/10E f 5/iN05E/P6.

Q1 I l ATTORNEY.

Patented May 7, 1940 UNITED STATES PATENT OFFICE LEVEL ALARM Arthur F. Sandberg, Jamaica, N. Y.

Application May 1, 1939, Serial No. 271,125 Claims. ((1200-83) This invention relates generally to machinery used to feed measured quantities of flavoring syrup tosoda water bottles, and aims to provide a device in the form of an automatic alarm B mounted in the syrup feed line, to warn the operator of the necessity of refilling the syrup feed source, the alarm being given a sufiicient time in advance of complete evacuation of the feed line to enable the operator to refill the supply without interfering with the continued filling of the bottles with the desired mixture of syrup and water. In the case of such machines, the bottles are passed along in regular succession and are automatically fed the desired amount of soda water 1 and syrup, and in the event that the syrup line should suddently run dry, a number of bottles will have passed on containing only the soda water without any syrup, before the operator has discovered the error, whereupon he must 2o stop the machine, refill the syrup supply, and discard the bottles which have been filled with water alone. The present invention, as abovementioned, overcomes these defects. The above and other objects will become appar- 25 ent in the description below, in which characters of reference refer to like-named parts in the accompanying drawing.

Referring briefly to the drawing, Figure 1 is an elevational View of the alarm device, illustrat- 30 ing its application to the syrup feed line, and containing also a wiring diagram.

Figure 2 is a plan view of the device.

Figure 3 is an elevational view of the device with the cover at the top removed.

35 Figure 4 is a cross-sectional view taken on the line 4-4 of Figure 3.

Figure 5 is a cross-sectional View taken on the line 55 of Figure 4.

Referring in detail to the drawing, the numeral 40 indicates a syrup feed line, either a pipe or a hose, which conveys syrup by gravity from a tank or the like ll situated at a point above the bottling machine, not shown. The representation of the tank H is herein made for the 45 purposes of clarification only, and is drawn relatively diminutively in comparison with the scale of the remainder of the drawings,

In the installation of the present invention, a T-union I2 is interposed in the hose H1, and to '50 the intermediate nipple is attached the threaded stem l3, through the medium of a reducing coupling l4.

The device I 5 itself consists of a pair of opposed complementary substantially conical shells I6 55 and I1, joined together by screws through their peripheral flanges 18. A disc or membrane IQ, of rubber or any other suitable material, is clamped between the flanges l8 and is normally A screw-threaded collar siu'rounds the opening 2| through the bottom of the shell l5, 5 and a collar 22 surrounds the smaller smooth opening '23 in the top of the shell it. A stem 24 is anchored in the center of the membrane l9 and extends upward through the opening 23, in which it is slidable. i

A ring 25 of composition or other insulating material, surrounds the collar 22, and has secured to its upper surface, in mutually opposed relation, a pair of metallic members it. The upper portion of the stem 24 is threaded and has clamped thereon, between a pair of nuts El, the projecting ear 29 of a yoke 28 of similar composition material. A metallic strip 38 is loosely mounted on the top of the yoke 28, and through the ends of the strip 30 and yoke 23, threaded 20 pins 31 project downwardly, the upper ends of the pins 3| being fixed to the strip 35. Nuts 32 are threaded on the pins 3| and between these nuts and the yoke 28 coiled springs 33 surround the pins. The pins 3| are positioned above the mem- 25 bers 26.

A plurality of loose spacer rings are mounted on the stem 24 between the lower nut Z'l and thecollar 22. A weight 34 is screwed on the top of the stem 24, and a removable slotted cap 35 0 is adapted to cover the contacts and mechanism on top of the shell l6. Lead wires 36 lead, through a conventional circuit opening and closing switch 31 mounted on the shell It, to an alarm 38 and a source of electric supply 39, as shown in 35 the wiring diagram of Figure 1.

In operation, with the device mounted in the syrup line as above-mentioned, and assuming the supply line from the syrup source to be full, a certain amount of theflowing syrup will rise up in- 4b to the stem l3, thus compressing the air enclosed under the membrane [9 and forcing the latter to bulge upward, as shown in Figure 4. In that position, the yoke 28 will be in elevated'position, being held up by the stem 24, and the lower tips of the pins 3! will lie clear above the strips 26. Assuming that the supply tank I I has become empty and the level of syrup in the pipe it is sinking lower and lower with respect to the T-union l2, the air pressure under the membrane 19 will correspondingly decrease. When the air pressure has decreased a sufiicient amount, the stem 24 will have fallen a suilicient distance to bring the tips of the pins 3! in contact with the strips 26, thus closing the circuit through the alarm. If

the stem 24 falls further, after the circuit has thus been closed, the yoke 28 will separate from the strip 30 and will compress the springs 33, thereby both assuring an equalized and steady contact between the pins 3| and the strips 26 and at the same time preventing a strain on the membrane I9 as the falling pressure thereunder causes it to pull down on the stem 24. The alarm will obviously continue to ring, unless switched off, until the supply tank I I has again been filled. It is obvious that by means of the nuts 21, the degree in variation of liquid level in the pipe I0 required to operate the alarm, may be varied at will. to force the stem 24 downward at the instant the level in the pipe 10 begins to decline below the predetermined level.

Obviously, modifications in form and structure may be made without departing from the spirit and scope of the invention.

I claim:

1. A pressure operated circuit controllercomprising a pair of opposed complementary shells joined together horizontally at their peripheries to form an upper and a'lower shell, a membrane having its peripheral edge clamped between said peripheries, each of said shells having an opening therethrough, a stem anchored in said membrane and extending slidably through the opening in said upper shell, a yoke secured to said stem and having pins depending therefrom, contact strips on said upper shell adjacent the free ends of said pins, said membrane normally urging said pins downward against said strips, an increase in air pressure in said lower shell causing bulging of said membrane and consequent movement of said stem upward, said movement causing said stem to lift said pins clear of said strips, said strips forming the stationary contact poles of an electric circuit closer and said yoke and pins forming the movable contact element thereof.

2. A pressure operated circuit controller comprising a pair of opposed complementary shells joined together horizontally at their peripheries to form an upper and a lower shell, a membrane having its peripheral edge clamped between said peripheries, each of said shells having an opening therethrough, a stern anchored in said membrane and extending slidably through the opening in said upper shell, a horizontal beam secured to said stem and having vertical pins slidably mounted in the ends thereof, a metallic strip loosely mounted on said beam and having the heads of said pins rigid thereon, said pins being threaded and having nuts thereon, coiled'springs surrounding said pins between said nuts and said beam, contact strips on said upper shell adjacent the free ends of said pins, said membrane normally urging said beam downward and consequentlysaid pins downward against said contact strips, an increase in air pressure in said lower shell causing bulging of said membrane and consequent movement of said stem upward, said movement causing said stem to lift said pins clear of said contact strips, the latter forming the stationary contact poles of an electric circuit closer and said metallic strip and said pins forming the movable contact element thereof, said coiled springs serving to reduce the strain on said membrane as the pressure in said lower shell to fall after said pins have contacted with said contact strips during the descent of said stem.

The weight 34 serves to aid the membrane 3. A pressure operated circuit controller comprising a pair of complementary shells joined together horizontally at their peripheries to form an upper and a lower shell, a membrane having its peripheral edge clamped between said peripheries, each of said shells having an opening therethrough, a stem anchored in said membrane and extending slidably through the opening in said upper shell, a yoke secured to said stem and having pins depending therefrom, contact strips on said upper shell adjacent the free ends of said pins, said membrane normally urging said pins downward against said strips, an increase in air pressure in said lower shell causing bulging 01' said membrane and consequent movement of said stem upward, said movement causing said stem to lift said pins clear of said strips, said strips forming the stationary contact poles of an electric circuit and said yoke and pins forming the movable contact element thereof, and means for longitudinally adjusting the position of said yoke on said stem.

4. A pressure operated circuit controller comprising a pair of opposed complementary shells joined together horizontally at their peripheries to form an upper and a lower shell, a membrane having its peripheral edge clamped between said peripheries, each of said shells having an opening therethrough, a stem anchored in said membrane and extending slidably through the opening in said upper shell, a horizontal beam secured to said stem and having vertical pins slidably mounted in the ends thereof, a metallic strip loosely mounted on said beam and having the heads of said pins rigid thereon, said pins being threaded and having nuts thereon, coiled springs surrounding said pins between said nuts and said beam, contact strips on said upper shell adjacent the free ends of said pins, said membrane normally urging said beam downward and consequently said pins downward against said contact strips, an increase in air pressure in said lower shell causing bulging of said membrane and consequent movement of said stem upward, said movement causing said stem to lift said pins clear of said contact strips, the latter forming the stationary contact poles of an electric circuit closer and said metallic strip and said pins forming the movable contact element thereof, said coiled springs serving to reduce the strain. on said membrane as the pressure in said lower shell to fall after said pins have contacted with said contact strips during the descent of said stem, and means for longitudinally adjusting the position of said beam on said stem.

5. A circuit closer comprising a base having a pair of spaced contacts fixed thereon, said base having an opening therethrough and having a stem slidably mounted in said opening, a beam on said stem, said beam having a. metallic strip loosely mounted thereon and having openings through its ends, pins anchored in said strip and extending slidably through said beam openings toward said contacts, said pins being threaded and having nuts thereon between said beam and their free ends, coiled springs on said pins between said nuts and said beam, said stem being moved into said base to bring said pins into contact with said contacts to close the circuit therethrough, said springs enhancing the security of the electrical contact between said pins and said contacts while said stem is retained in said closedcircuit position.

ARTHUR F. SANDBERG. 

